1. Field of the Invention
The invention relates to a drive module for a vehicle.
2. Description of the Related Art
A drivetrain of a hybrid vehicle has a hybrid drive that includes an internal combustion engine, an electric machine and a transmission interposed between the hybrid drive and a drive output. The electric machine preferably is coupled permanently to a transmission input shaft of the transmission, and the internal combustion engine either is coupled to or decoupled from the transmission depending on the switching position of a separating clutch. Both the electric machine and the internal combustion engine can impart a drive torque to the transmission input shaft when the separating clutch is closed. By contrast, only the electric machine can impart a drive torque to the transmission input shaft of the transmission when the separating clutch is open. The electric machine, the transmission and the separating clutch form a hybrid module with an air-cooled cavity formed between the electric machine and the transmission. During operation, heat is generated at the electric machine of the hybrid module, and the heat must be dissipated in an effective manner for cooling purposes. The same applies to an electric module of an electric vehicle that comprises an electric machine and a transmission, but no separating clutch.
U.S. Pat. No. 6,175,171 discloses an electric drive motor in the form of an external-rotor motor. Concentric cooling fins are formed on a radial surface of a stator-side support that faces toward a rotor of the motor.
U.S. Pat. No. 6,114,784 discloses a cooling concept for a hybrid drive where pairs of cooling jackets are formed in a stator of an electric machine. Coolant inlet openings function for conducting coolant to the cooling jackets, whereas coolant outlet openings function for discharging the coolant from the cooling jackets. A coolant return flow section connects each pair of cooling jackets.
It is possible for electric machines to be cooled to a certain extent with the cooling concepts known from the prior art. However, there is a demand for a drive module that permits effective cooling at high rotational speeds of the electric machine and in the presence of intense heat generation.
The invention is based on the object of providing a novel drive module for a vehicle.